Question

Will Medal
Please help!!
Use Quadratic formula to solve for x:
(x+2)(x-1) = 5

Answer 1

Start off by putting into \[ax^2+bx+c=0\] form

Answer 2

ok, wait let me solve it first

Answer 3

Take your time

Answer 4

ok, x^2 +1x -7

Answer 5

Good now we have the quadratic formula which is the following \[x = \frac{ -b \pm \sqrt{b^2-4ac} }{ 2a }\] where a = 1, b= 1, and c = -7

Answer 6

ok, wait again sorry

Answer 7

Answer is 2,-1

Answer 8

Are you sure?

Answer 9

yes

Answer 10

no no i am wrong wait

Answer 11

the answer is 2.15 and -3.15

Answer 12

i took the wrong equation

Answer 13

\[x= \frac{ -1 \pm \sqrt{1^2-4(1)(-7)} }{ 2(1) } \implies x = \frac{ -1 \pm \sqrt{29} }{ 2 }\] correct?

Answer 14

yes

Answer 15

That should \[x \approx -3.19,~~ \text{and}~~ x \approx 2.19\]

Answer 16

can i ask you an another quetion pls

Answer 17

Sure thing

Answer 18

Use Quadratic formula to solve for x:
\[x + \frac{ 1 }{ x+2 } = 4\]

Answer 19

Same thing as earlier, try putting it into \[ax^2+bx+c=0\]

Answer 20

how will i do that

Answer 21

You can multiply through by (x+2)

Answer 22

??

Answer 23

I mean you can find a common denominator which in this case is (x+2) if you like

Answer 24

can we cross multiply

Answer 25

You can do as following \[\frac{ 1 }{ x+2 }=4-x \] now you may do as you like

Answer 26

\[\frac{ 1 }{ (x+2) } = (4-x)\]

Answer 27

ok

Answer 28

wait

Answer 29

is it = to 4x-x-5??

Answer 30

Hmm, not quite, \[\frac{ 1 }{ (x+2) } = (4-x) \implies 1 = (4-x)(x+2)\]

Answer 31

yeah then we multiply (4-x)(x+2) = 4x - x +6

Answer 32

an we bring it to the other side

Answer 33

-4x + x -6 + 1

Answer 34

= -4x + x -5 = 0

Answer 35

right??

Answer 36

Remember, we want our equation in \[ax^2+bx+c=0\] form, so what you wrote, does that make sense?

Think of what you did in the previous problem

Answer 37

x^2-4x-5

Answer 38

= 0

Answer 39

\[(4-x)(x+2)=1 \implies 4x+8-x^2-2x =1 \implies 2x+8-x^2=1 \] so we can set this up as \[x^2-2x-7=0\]

Answer 40

ok. sorry i was offline, i had a lag

Answer 41

answer is = 1.9, -0.9 right??

Answer 42

@iambatman

Answer 43

Can you show how you got that?

Answer 44

ok